1. Field of Endeavor
The present application relates to microelectrode arrays and methods of fabrication, and particularly to incorporating an optical waveguide into a neural interface.
2. State of Technology
This section provides background information related to the present disclosure which is not necessarily prior art.
The current method to deliver light to light-sensitive cells in the brain and other parts of the nervous system is to use fiber optic waveguides. These fibers are commercially available and can be made as small as 50 um in diameter, however they are not ideal. At 50-200 um in diameter, the fibers are still too large to implant and study many important regions of the brain. Each fiber provides only one point of light source and one wavelength. There is a need for a light delivery system that is able to deliver multiple wavelengths as needed and in multiple areas, all with a minimal device footprint. To achieve this with fiber optics, 3 different fibers each at 50-200 um each would have to be implanted, and still this would only provide 3 light sources. Optical fibers also have low light delivery efficiency. Often a 100 mW source is required to deliver 1-5 mW to the desired site. The fiber optics is implanted separately and relatively far from the signal recording device. There is a need for a system wherein the recording electrodes are placed within microns of the delivered light source and the stimulated cells.
The current fiber optic waveguide system for delivering light to light-sensitive cells in the brain and other parts of the nervous system relies upon optical fibers that are too large to implant and study many important regions of the brain. The current fiber optic system is the only reliable method currently available, however it is not ideal. Each fiber is relatively large, can provide only one light source, one wavelength at time, and a high power loss by the time the light reaches its destination. In addition, the fiber is often implanted separately and relatively far from the signal recording device. Recording arrays with an attached fiber are made manually, leading to high variability and long labor time.